In just two weeks, the record-breaking Zhangjiajie bridge saw 10 times the expected number of visitors.

The problem with building tourist attractions out of glass is the throngs of, well, tourists. They may turn up in droves and test the structural limits of what you’ve built—which will make even the most even-keeled engineers nervous.

No one is more familiar with this problem than Chinese government officials, who, late last week, were forced to close the newly opened Zhangjiajie Grand Canyon Glass Bridge in a remote part of the Hunan province due to inordinate numbers of visitors.

According to a story in the Los Angeles Times, the highest and longest glass-bottomed bridge in China was built to accommodate up to 660 people at once and 8,000 people a day, but nearly 10 times that many turned out to see (and practice yoga or take selfies on) it. You read that right—since the bridge opened on August 20, it attracted about 80,000 people every day at roughly US$20 a pop.

All told, the bridge was only open 13 days before it was shut down.

The bridge certainly is a sight to behold: 1,410 feet long, 20 feet wide, and almost 1,000 feet off the ground. For comparison, the glass-bottomed Grand Canyon Skywalk cantilevered out over the Grand Canyon in Arizona is only about 70 feet long.

Mid-span of the Zhangjiajie Grand Canyon Glass Bridge, visitors can look straight down through the glass panels to see a lush valley bookended by sandstone cliffs. An article on CNN noted that the region in Zhangjiajie Park is said to have inspired the scenery for the sci-fi movie Avatar.

Officials did not say when the Zhangjiajie Grand Canyon Glass Bridge would reopen, but noted that during the closure they plan to improve parking lots, ticket booking, customer service, and more. Travelers who prepurchased tickets for the bridge likely will have the chance to rebook for a later date.

In the meantime, China has other glass-bottomed bridges, such as Hao Han Qiao, or “Brave Man’s Bridge,” in Shiniuzhai National Geological Park. That bridge opened in September 2015 and closed temporarily for a few weeks after one of the glass panels cracked.

Perhaps that experience made Zhangjiajie engineers paranoid? We certainly wouldn’t blame them for that.

Matt Villano is a freelance writer and editor based in Healdsburg, California. In nearly 20 years as a full-time freelancer, he has covered travel for publications including TIME, the Wall Street Journal, the New York Times, Sunset, Backpacker, Entrepreneur, and more. He contributes to the Expedia Viewfinder blog and writes a monthly food column for Islands magazine. Villano also serves on the board of the Family Travel Association and blogs about family travel at Wandering Pod. Learn more about him at Whalehead.com